816511981583 has 2 divisors, whose sum is σ = 816511981584. Its totient is φ = 816511981582.

The previous prime is 816511981577. The next prime is 816511981603. The reversal of 816511981583 is 385189115618.

816511981583 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 816511981583 - 2⁴ = 816511981567 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (816511981513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 408255990791 + 408255990792.

It is an arithmetic number, because the mean of its divisors is an integer number (408255990792).

Almost surely, 2^816511981583 is an apocalyptic number.

816511981583 is a deficient number, since it is larger than the sum of its proper divisors (1).

816511981583 is an equidigital number, since it uses as much as digits as its factorization.

816511981583 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2073600, while the sum is 56.

The spelling of 816511981583 in words is "eight hundred sixteen billion, five hundred eleven million, nine hundred eighty-one thousand, five hundred eighty-three".